Manual

NAME

grub-btrfsd - An OpenRC daemon to automatically update the grub menu with grub-btrfs_(8)

when a new btrfs snapshot is created.

SYNOPSIS

grub-btrfsd [-h, --help] [-c, --no-color] [-r, --recursive] [-s, --syslog] [-t, --timeshift-auto] [-o, --timeshift-old] [-v, --verbose] SNAPSHOTS_DIRS

DESCRIPTION

Grub-btrfsd is a shell script which is meant to be run as a daemon. Grub-btrfsd watches a directory where btrfs-snapshots are created or deleted via inotifywait and runs grub-mkconfig (if grub-mkconfig never ran before since grub-btrfs was installed) or /etc/grub.d/41_snapshots-btrfs (when grub-mkconfig ran before with grub-btrfs installed) when something in that directory changes.

OPTIONS

SNAPSHOTS_DIRS

This argument specifies the (space separated) paths where grub-btrfsd looks for newly created snapshots and snapshot deletions. It is usually defined by the program used to make snapshots. E.g. for Snapper this would be /.snapshots. It is possible to define more than one directory here, all directories will inherit the same settings (recursive etc.). This argument is not necessary to provide if --timeshift-auto is set.

-r –recursive

Watch snapshot directories recursively. This is useful if the snapshots are stored in subdirectories of the specified directories. If this flag is not set, only the specified directories are watched.

-s, –syslog

Write the output of the daemon to syslog (NOTE: this option will be deprecated in the future. Making the daemon write to syslog the default behavior). If this flag is not set no logging is done. However, messages are printed to stdout and stderr.

-t, –timeshift-auto

This is a flag to activate the auto detection of the path where Timeshift stores snapshots. Newer versions (>=22.06) of Timeshift mount their snapshots to /run/timeshift/$PID/backup/timeshift-btrfs. Where $PID is the process ID of the currently running Timeshift session. The PID is changing every time Timeshift is opened. grub-btrfsd can automatically take care of the detection of the correct PID and directory if this flag is set. In this case the argument SNAPSHOTS_DIRS has no effect.

-o, –timeshift-old

Look for snapshots in /run/timeshift/backup/timeshift-btrfs instead of /run/timeshift/$PID/backup/timeshift-btrfs. This is to be used for Timeshift versions <22.06.

-v, –verbose

Enable verbose output for the inotifywait command. This will print the events that are being watched for, which can be useful for debugging purposes.

-h, –help

Displays a short help message.

CONFIGURATION

The daemon is usually configured via the file /etc/conf.d/grub-btrfsd on openrc-init systems and sudo systemctl edit --full grub-btrfsd on systemd systems. In this file the arguments (See OPTIONS), that OpenRC passes to the daemon when it is started, can be configured.

NOTES

A common configuration for Snapper would be to set SNAPSHOTS_DIR to /.snapshots and not to set --timeshift-auto. For Timeshift --timeshift-auto is set to true and SNAPSHOTS_DIR can be left as is.

FILES

/etc/conf.d/grub-btrfsd /usr/lib/systemd/system/grub-btrfsd.service

SEE ALSO

btrfs(8) btrfs-subvolume(8) grub-btrfsd-conf(8) grub-mkconfig(8) inotifywait(1) openrc(8) rc-service(8) timeshift(1)

COPYRIGHT

Copyright (c) 2022 Pascal Jäger Copyright (c) 2025 Michael Lee Schaecher